Java 3D Research Articles

JaSTA-3: Light scattering simulations for heterogeneous aggregate

JaSTA-3: Light scattering simulations for heterogeneous aggregate

Modeling the Breakup of Clusters Induced by Internal Repulsion

In nanoparticles system, particles (or clusters) can aggregate into big-scale clusters, which also can break into small ones by the change of internal conditions. For this purpose, a breakup model was proposed and a JAVA program was developed to simulate the process based on the classic Cluster-Cluster Aggregation (CCA) model. In the simulation, a single cluster, which is gotten from the CCA, breaks into small ones firstly, and then these break into smaller and smaller ones sequentially abiding by specified rules. It is found that clusters present various structure under different parameters in the cube system. Meanwhile, the process visualization can be well displayed by JAVA 3D figures dynamically, and some data analysis can be performed spontaneously based on the data files recorded by the program.

Development of Multimedia Environment for Viewing the State of Stress in a Differential Element

The aim of this work is to present a tool developed in a multimedia environment of a cilitate the understanding of the state of plane stress at an infinite simal element, which is directed to lectures in Mechanics of Materials courses. This multimedia resource was developed in Java 3D API, liked an applet, as it is a simple language whose programs can run on all operating system platforms, using the virtual machineconcept. The multimedia resource determines the strains caused by forces acting in a solid body. Usingthis tool the learning process can be more efficiently, and the view of results at an differential element in the state of plane stress can be easier too.

A geostationary Earth orbit satellite model using Easy Java Simulation

We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modelled using a Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using a simple constant angular velocity equation. We discuss four computer model design ideas: (1) a simple and realistic 3D view and associated learning in the real world; (2) comparative visualization of permanent geostationary satellites; (3) examples of non-geostationary orbits of different rotation senses, periods and planes; and (4) an incorrect physics model for conceptual discourse. General feedback from the students has been relatively positive, and we hope teachers will find the computer model useful in their own classes.

An Implementation of 3D Landslide Geological Modeling and Visualization

Three-dimensional (3D) geological modeling and visualization of landslide is very important for landslide monitoring and stability evaluation. Unfortunately there have not been very efficient methods to realize this modeling and visualization process currently. An implementation of 3D landslide geological modeling and visualization based on a hybrid data structure of TIN and GTP is introduced in this paper. The proposed implementation method includes three sections: pre-processing terrain data for known or history data; 3D modeling of landslide terrain surface, slip surface and geological structure surfaces; construction of 3D landslide geological model and 3D visualization of landslide model through java 3D API. The introduced method contributes to a new approach to landslide research.

The 3D Computer Game Design Using Java 3D

In this thesis, the two 3D computer games were designed by Java 3D. In the first game, by using 3DMax, one aircraft carrier, one helicopter, submarines, warships, and destroyer escorts etc were designed. By using Loader3DS of MicrocrowLoader in Loader3DS1_2.jar or ModelLoader of Java 3D, these 3D models are loaded into the Java 3D. The second 3D game displays the 3D fighting and collision of tanks. This function is very important for the 3D game design. By using textures, the different appearances of 3D models were designed. By using Java 3D classes such as Alpha and PositionPathInterpolator and Sounds etc, the motions of 3D models and interactions and the sounds were defined.

High-Accuracy Shape Construction of Porcelain and Exhibiting on Web

The key of 3D measurement technology based on coded structured light for high-accuracy reconstruction of porcelain exhibited on Web, is to ensure measurement accuracy and anti-interference capability on high reflectance surface. So an edge Gray code method for structured light system and related technologies are proposed under interference by high reflectance ratio and color of measured surface. Firstly, encoding and decoding principles by Gray code stripe edge reduce theoretical quantization error and decoding error against traditional Gray code, so measurement accuracy is improved. Secondly, stripe edge sub-pixel location method based on grey curve intersecting points is designed to reduce edge location error caused by diffusion from white stripe to black stripe. Measurement system was established according to mathematic model. Experimental results show that error of measured high reflectance unicolor standard plane is 0.60.8mm, and reconstructed porcelain shape has same visual effect as the real one. Finally, based on Java 3D, interactively exhibiting on Web was explored.

Three Order Bezier Surface and Racing Car Conception Model Design Using Java 3D

By using Bezier surface matrix formula and Bezier surface control points and through merging different Bezier surfaces, the car model was produced. By using texture and transparence and other functions of Java 3D, the tyres and the wind screen of the car and the exhibition platform were designed. By defining the moving and rotation actions, the motions of the car model were designed. All functions were implemented by Java and Java 3D.

Virtual human simulation method based on Java 3D

The paper proposed a simulation method of virtual human by combining 3DS MAX, MS3D and Java 3D programming, which could achieve a relatively realistic strong interaction effect on virtual human. First, 3DS MAX role animation techniques were taken as a tool to construct the human static and dynamic models, then the underlying basic action footage were transformed into MS3D format for skeletal animation model interface of Java 3D, last the high-level behaviors of virtual human were controlled by Java 3D programming. The experiments demonstrate that the method is effective for the division of responsibilities between role modeling, motion simulation and behavior control, and it is also suitable for the multi-role, complex motions of the virtual human simulation in the network environment.

Genetic Algorithm Based Solution for TSP on a Sphere

The Traveling Salesman Problem (TSP) is one of the extensively studied combinatorial optimization problems. Various exact or approximation algorithms are devised for solving Euclidean TSP that determine the shortest route through a given set of points in 3-dimensional Euclidean space. In this paper, we proposed a genetic algorithm-based solution for TSP where all points are on the surface of a sphere. A Java-based interactive visualization tool is also developed using Java 3D and optimization results obtained for different problem sizes are presented.

Automating Landscape Illustration with Pen and Ink Style Rendering

This paper introduces object space procedures for extracting silhouettes, slope lines, and drainage features from digital elevation models (DEMs) to direct the rendering of landform features in the style of pen-and-ink landscape illustrations. Unlike image space procedures which generally extract feature information through 2-dimensional (2D) rendered image processing techniques, object space procedures operate directly on 3-dimensional (3D) surface models. The ultimate goal of this work is to produce fully automated tools that can imitate the styles characterized by the traditional pen-and-ink techniques of Lobeck, Imhof, Raisz, and other scientific illustrators to bring the beauty of their effective and economical visual techniques to automated cartographic environments. Through the implementation of a Java 3D application programming interface (API) prototype, a testing platform was established for the application of stylistic elements to linework representing surface form lines. This paper explores the aesthetic effects of silhouette lines, creases, and slope lines on the rendering of terrain features. It also introduces the use of adaptively resampled triangulated irregular networks (TINs) as a basis for perspective rendering applications.

Path planning on a cuboid using genetic algorithms

The Traveling Salesman Problem (TSP) is one of the most extensively studied problems in the fields of Combinatorial Optimization and Global Search Heuristics. A variety of heuristic algorithms are available for solving Euclidean TSP, and Planar TSPs. However, optimization on a cuboid has potential applications for areas like path planning on the faces of buildings, rooms, furniture, books, and products or simulating the behaviors of insects. In this paper, we address a variant of the TSP in which all points (cities) and paths (solution) are on the faces of a cuboid. We develop an effective hybrid method based on genetic algorithms and 2-opt to adapt the Euclidean TSP to the surface of a cuboid. The method was tested on some benchmark problems from TSPLIB with satisfactory results. A web-based interactive visualization tool has also been developed using Java 3D, and optimization results for different point densities on the cuboid are presented.

Development of Architectures for Internet Telerobotics Systems

This paper presents our experience in developing and implementing Internet telerobotics system. Internet telerobotics system refers to a robot system controlled and monitored remotely through the Internet. A robot manipulator with five degrees of freedom, called Mentor, is employed. Client-server architecture is chosen as a platform for our Internet telerobotics system. Three generations of telerobotics systems have evolved in this research. The first generation was based on CGI and two tiered architectures, where a client presents a Graphical User Interface to the user, and utilizes the user's data entry and actions to perform requests to robot server running on a different machine. The second generation was developed using Java. We also employ Java 3D for creating and manipulating 3D geometry of manipulator links, and for constructing the structures used in rendering that geometry, resulting in 3D robot movement simulation presented to the users (clients) through their web browser. Recent development in our Internet telerobotics includes object recognition through image captured by a camera, which poses challenging problem, giving the undeterministic latency of the Internet. The third generation is centered around the use of CORBA for development platform of distributed internet telerobotics system, aimed at distributing task of telerobotics system.

Synchronous collaborative systems for distributed virtual environments in Java

This paper presents a 3D-distributed virtual environment, which allows for the creation of applications to enable multiple users to collaboratively interact in, and communicate about, a virtual world. This virtual environment is used to primarily support a flight simulator application by providing communications routines and networking synchronisation between the client and the server. Four server client synchronisation methods were developed and compared. The method of transparent synchronisation with non-blocking I/O has been found to be the best method for maintaining synchronisation among distributed virtual environments using Java. The successful creation of the distributed virtual environment and the positive results collected in the supporting experimental data, leads to the conclusion that Java, with the addition of the non-blocking I/O Java.NIO.channels API and the Java 3D API, can be successfully used to create high-performance distributed 3D-virtual environments.

Observer-Conditioned-Observable Design Pattern.

The Observer-Conditioned-Observable (OCO) combines digitizing and transcoding of numeric change events. During the processing of numeric events, the transcoder converts the number from one range into another while preserving the mathematical integrity of the value. Numeric controllers that generate such events can be based in floating point numbers or integer numbers. For example, the JSpinners of Swing are based in floating point numbers, but JSliders are based in integers. Thus, the dynamic range of the JSliders is typically many orders of magnitude away from the dynamic range of the spinners. Even worse, changes in a numeric model can propagate to an integer-based spinner. This leads to quantization error and back propagation of the re-quantized value. Interactive programs use multiple viewers and controllers to alter an underlying numeric model. These can update each other in an observer-observable loop that can propagate unintended and unmanaged digitization errors. The OCO design pattern breaks the loop and maintains control of the numerical values. The interception of changes is done via a modification of the equals method. If two numbers are equal (to within a user defined tolerance) propagation is suppressed. Thus, the digitizer re-samples and re-quantizes the numeric event. Another potential problem arises when multiple viewer-controllers for the same number model employ differing scales. For example, sliders can range between two integer numbers (e.g., 0...100); whereas the floating-point number that we would like to model ranges from 0.0 and 1.0. We demonstrate a procedure for translating one value into the range of another, without error or feedback. OCO also samples events in time. This band limits the events to a level deemed reasonable for the application. The veto design pattern is not new, nor, for that matter, is a numeric veto design pattern. However, a numeric veto design pattern that is sensitive to the magnitude and rate of the numeric change is new. Also new is the conversion of one numeric range into another during the model view controller construction. Thus, we have arrived at a new name for our design pattern, called the Observer-Conditioned-Observable design pattern (OCO). We apply the OCO design to the input of numbers that not only are floating point, but that have a dynamic range. The goal of our system is to allow the user to sweep large spans of dynamic range and “zoom in” to very high precision variation in areas of interest, for example bifurcation points in a dynamical system model. Our particular application involves 16 degrees of freedom for controlling the compound iteration of several hundred Java 3D linear transformations, in real-time. Other applications include scientific/mathematical simulation, Monte Carlo methods and numeric solution of systems of equations. These applications are critically dependent on initial conditions.

Hybrid image‐based collision detection in Java 3D

AbstractCollision detection is highly important in computer graphics and virtual reality. Most collision detection methods are object‐based, relying on testing the geometrical interference of objects, and their performance therefore depends on the geometrical complexity of the objects. Recently, image‐based methods have gained increasing acceptance for their simplicity in implementation, robustness with respect to the object geometry, and the potential to distribute the computational burden onto graphics hardware. However, all existing image‐based methods require direct calls to OpenGL, but so far there is no direct way to access OpenGL through the Java 3D API. Although Java 3D provides its own built‐in collision detection classes, they are either incorrect or inefficient. In this paper, we present a hybrid image‐based collision detection method in Java 3D, which incorporates the Java 3D built‐in collision detection and the image‐based collision detection in our specially devised scene graph. In addition, we take advantage of the fact that the 3D position of successive offscreen views (i.e. virtual views perceived by the probing object) does not change significantly and thereby reduce the occurrences of offscreen rendering, so that the collision detection becomes even faster (up to 50% in our case). Experimental results prove the correctness and efficiency of our method. Copyright © 2006 John Wiley & Sons, Ltd.

The Rutgers Arm, a Rehabilitation System in Virtual Reality: A Pilot Study

Stroke is one of the leading causes of death and disability worldwide. Its prevalence calls for innovative rehabilitation methods. The Rutgers Arm is a novel upper extremity rehabilitation system consisting of a low-friction table, three-dimensional (3D) tracker, custom forearm support, PC workstation, library of Java 3D virtual reality (VR) exercises, clinical database module, and a tele-rehabilitation extension. The system was tested on a chronic stroke subject, under local and tele-rehabilitation conditions, over 5 weeks of training. Results show improvements in arm motor control and shoulder range of motion, corresponding to improved Fugl-Meyer test scores. Exercise duration, level of difficulty, and patient motivation were maintained under tele-rehabilitaion. A 1-week retention trial showed that gains were maintained.

A Modular Framework for Development and Interlaboratory Sharing and Validation of Diffusion Tensor Tractography Algorithms

This Technical Note describes a novel modular framework for development and interlaboratory distribution and validation of 3D tractography algorithms based on in vivo diffusion tensor imaging (DTI) measurements. The proposed framework allows individual MRI research centers to benefit from new tractography algorithms developed at other independent centers by "plugging" new tractography modules directly into their own custom DTI software tools, such as existing graphical user interfaces (GUI) for visualizing brain white matter pathways. The proposed framework is based on the Java 3D programming platform, which provides an object-oriented programming (OOP) model and independence of computer hardware configuration and operating system. To demonstrate the utility of the proposed approach, a complete GUI for interactive DTI tractography was developed, along with two separate and interchangeable modules that implement two different tractography algorithms. Although the application discussed here relates to DTI tractography, the programming concepts presented here should be of interest to anyone who wishes to develop platform-independent GUI applications for interactive 3D visualization.

Mechanical design and locomotion control of a homogenous lattice modular self-reconfigurable robot

In this paper, we propose a novel, 3D, like cubic shape, modular self-reconfigurable (MSR) robot named M-Cubes. Its key mechanical components are analyzed in detail. By communicating with the neighboring modules, each unit employs its automatic lock device composed of a pin and a hole on each connection plane which can connect or disconnect with neighboring modules. The M-Cubes system consisting of many identical modules cooperates to change their connection, and then the whole structure transforms into arbitrary structure. Furthermore, we describe its locomotion control based on the driving function and the adjacency matrix which is effective for solving the computationally difficult problem and optimizing the system motion path during the self-reconfiguration process. Finally, a simulation experiment using java 3D technology, proved the new method for controlling modular robot is robust and useful.

Object Oriented Design of a Finite Element Code in Java

This paper presents the object oriented ap- proach to programming the finite element method using the Java language. The developed finite element code consists of ten Java packages. Three main methods are related to generation of finite element models, solution of elastic and elastic-plastic boundary value problems, and visualization of models and solution results. Object- oriented model of the code is described. It is demon- strated that Java 1.5 new features are useful in develop- ment of the finite element code. Java 3D is used for visu- alization of models and results. keyword: Object oriented approach, Java, Java 3D, Fi- nite element method, Elastic, Elastic-plastic, Visualiza- tion.